System for construction of monolithic concrete tanks and silos

ABSTRACT

A scaffold mechanism for constructing a cylindrical building, such as a concrete silo, with a horizontal platform supported on a plurality of fixed arms having telescopically extensible ends with the platform vertically supported on triangularly positioned peripheral vertical ground supported masts having pins placed in openings for locking the platform at vertical increments and having hydraulic lifters on each of the masts for raising the platform for each pouring of new concrete courses. A ground supported main central mast extends up through the platform and supports, at its upper end, cranes which are pivotally supported on the main mast for lifting the forms to reset positions, elevating concrete to a bucket cart which rolls peripherally around on the platform, or suspending and rotating hoses used for the placement of concrete when pumping is used in lieu of elevating concrete to a bucket cart. A hydraulic motor driven pump is carried on the platform for operating the elevating mechanism, the cart and the cranes.

United States Patent [191 Miller et a1.

[ Oct. 7, 1975 1 SYSTEM FOR CONSTRUCTION OF MONOLITI-IIC CONCRETE TANKS AND SILOS [76] Inventors: Robert E. Miller, 1210 Pippin Court; Thomas E. Miller, 480 E. Maple Lane, both of Mequon, Wis. 53092 [22] Filed: Nov. 30, 1973 [21] Appl. No.: 420,610

[52] US. Cl 182/128; 182/129 Primary Examiner-Reinaldo P. Machado Attorney, Agent, or FirmHill, Gross, Simpson, Van

Santen, Steadman, Chiara & Simpson [57] ABSTRACT A scaffold mechanism for constructing a cylindrical building, such as a concrete silo, with a horizontal platform supported on a plurality of fixed arms having telescopically extensible ends with the platform vertically supported on triangularly positioned peripheral vertical ground supported masts having pins placed in openings for locking the platform at vertical increments and having hydraulic lifters on each of the masts for raising the platform for each pouring of new concrete courses. A ground supported main central mast extends up through the platform and supports, at its upper end, cranes which are pivotally supported on the main mast for lifting the forms to reset positions, elevating concrete to a bucket cart which rolls peripherally around on the platform, or suspending and rotating hoses used for the placement of concrete when pumping is used in lieu of elevating concrete to a bucket cart. A hydraulic motor driven pump is carried on the platform for operating the elevating mechanism, the cart and the cranes.

17 Claims, 9 Drawing Figures U.S. Patent Oct. 7,1975

FIG]

U.S. atent 00. 7,1975 Sheet 2 of5 3,910,379

US. Patent Oct. 7,1975 Sheet 3 of5 3,910,379

r VALVE BANK l v MOTOR & PUMP & CONTROL 52 OIL TANK FIG.3

US. Patent (M11975 Sh66t4 of5 FlG.6

US. Patent Oct. 7,1975

Sheet 5 of 5 FIG] SYSTEM FOR CONSTRUCTION OF MONOLITI-HC CONCRETE TANKS AND SILOS BACKGROUND OF THE INVENTION The present invention relates to a mechanism and a system for the construction of variable diameter monolithic concrete silos of varying heights for any and all types of bulk storage.

In the construction of silos and other cylindrical concrete structures which must be built to a considerable height, it has heretofore been the practice to erect scaffolding which must be constructed with considerable effort and time and to support scaffolding structure solely on the silo construction itself. Supporting solely on the silo construction is insecure and unreliable and requires satisfactory hardening of the concrete before changes in height can be effected. Further, in constructions heretofore available, changes in diameter of the silos could not be accommodated without providing alternate parts for each different silo diameter or without substantial complete reconstruction of the scaffolding mechanism. It was also heretofore difficult to handle and pour the concrete for the silos.

It is important to be able to readily and quickly raise the scaffolding as the silo is being constructed to permit the silo to be constructed in vertical increments. The present system employs forms which are set up in cylindrical form so that an annular silo wall is poured in incremental heights. The scaffolding is self-supported within the annular silo, and the scaffolding functions as a working platform to support personnel and materials and cranes used to elevate both the forms for a new setting and fresh concrete used to pour the silo wall, all from a position within the silo, The self-supporting capability of the scaffolding is unique in that it does not place stress on the walls, but the silo walls serve merely to provide lateral stabilization and center the scaffolding equipment.

An overall objective of the present invention is to provide a mechanism and system for pouring concrete silos which can be operated with less effort and less construction time than with mechanisms and/or systems heretofore available.

A further object of the invention is to provide a scaffolding mechanism capable of being used to form silos of variable diameters on the order of to 34 feet wherein the scaffolding can be moved incrementally upwardly with a minimum of operators and a maximum of safety.

A still further object of the invention is to provide a scaffolding mechanism which is self-supporting within a circular silo and has a substantial greater stability than mechanism and/or systems heretofore available and can be readily andsafely raised upwardly in steps to sequentially pour successive vertical sections of a circular silo.

In the economics of storage buildings, a cylindrical concrete silo is superior in design and protection capabilities to substantially all types of buildings. It is also relatively inexpensive to construct and has a long life. However, with equipment heretofore available, the time and difficulty of construction have created disadvantages. With the variation in crop production in different parts of the world, it is essential to the preservation of the crops that economical readily available storage facilities be available, and it is accordingly a feature of the invention to provide a mechanism which substantially reduces the cost and effort in constructing circular tower-like concrete buildings and enables the use of a single system of equipment for building constructions of varying desirable diameters with a minimum of adjustment. While the scaffolding arrangement herein disclosed and described is primarily designed for use for building monolithic concrete silos, it will be observed that it can be used to advantage for the construction of stave or block silos and other constructions of a circular nature requiring scaffolding.

Other objects, advantages and features will become more apparent with the teaching of the principles of the present invention, as will equivalent structures and methods which are intended to be covered herein, in the specification, claims, and drawings, in which:

DRAWINGS FIG. 1 is a perspective view of a mechanism assembled and operating in accordance with the principles of the present invention;

FIG. 2 is another perspective view of the mechanism of FIG. 1;

FIG. 3 is a somewhat schematic fragmentary top plan view of the mechanism;

FIG. 4 is a fragmentary elevational view of one of the arms taken substantially along the section IVIV of FIG. 2;

FIG. 5 is another fragmentary view of one of the arms taken substantially along the line V\/ of FIG. 2 with parts removed for clarity.

FIG. 6 is an elevational view of the mechanism with parts removed for clarity;

FIG. 7 is a fragmentary elevational view showing the operation of the mechanism for raising the platform;

FIG, 8 is a fragmentary elevational view of a portion of the mechanism; and

FIG. 9 is a fragmentary detailed view showing locking mechanism for supporting the platform.

DESCRIPTION The mechanism has a horizontal scaffolding platform 10 which is generally circular in shape for being located within the circular forms used to contain concrete to form the circular silo. The platform supports personnel, materials and distribution systems for the placing of the fresh concrete.

The scaffold platform is supported on a main center mast l1 and three peripherally located outer masts 12, 13 and 14. The masts are ground supported on the floor of the silo, and each has a flat base shown respectively at 15, 16,17 and 18 for the masts 11, 1213 and 14. The

.masts are cylindrical in shape. As will be seen from the continuing description of the mechanism, the design is particularly well adapted to the use of stock steel which does not require expensive machining or have expensive tolerance requirements. The parts are utilized in such a relationship that optimum strength is attained, and the scaffolding unit is constructed and maintained without excess expense of many machined parts, and the parts can be readily replaced with wear or breakage, although the entire unit is ruggedly constructed and is capable of long operating life without special maintenance or attention.

In accordance with the concept of the invention, the platform 10 is raised in increments as the sections of forms are set and poured. The platform and hoist mechanisms are fully supported on the vertical masts and do not depend for vertical support upon the silo being built. Lateral stabilization alone is provided by the silo for the peripheral vertical masts so that the strength of the forms and/or of the freshly poured concrete is not relied upon for supporting the mechanism as has been the case with a number of mechanisms and- /or systems heretofore available.

The peripheral masts 12, 13 and 14 are laterally tied to the concrete wall 22a at sufficient intervals to laterally stabilize the mechanism. This is accomplished by means of a concrete insert or lug cast in the wall at said intervals adjacent to the inner form 24 at the location of the peripheral masts 12, 13 and 14. Thereupon, when the inner forms 24 are removed, exposing said lug or insert, a bracket ties the individual peripheral masts 12,, 13 and 14 to the concrete wall 2.2a using the lug or insert. The center mast 11 is laterally stabilized at corresponding intervals by means of radial struts. incrementally longer than the radius of the building, radiating from the center mast to the inside face of the concrete wall 22a.

The scaffold platform includes a plurality of evenly spaced radially extending arms 19. The arms have an inner part 19 which are square tubular steel and receive at their outer ends telescoping extension arms 20. The extension arms telescope into the inner arms 19 and are adjusted to the diameter of silo to be constructed A plurality of holes 2012 are formed in the outer telescoping arms, and the arms are locked in their adjusted position by pins 20a which slide through aligned holes through the arms 19 and through the holes 20b in the extendable arms. Thus, the same unit can be adjusted to construct a silo in the range of 20 to 34 feet in diameter without requiring change in the basic mechanism. The contractor can set up the unit on the job and with little effort, adjust it to the size of the building to be poured.

On the top of the arms are secured decking sections 20c which provide a platform for the workmen to work on and store materials, and for'peripheral rolling move-- ment of the concrete dispensing cart 41, FIG. 2, or for supporting hose, FIG. 6, used for the placement of concrete when pumping. I

As shown primarily in FIG. 6, the inner ends of the arms 19 are supported on a sleeve 26 on the main mast II. The sleeve has annular ,disk flanges '27 and 28 welded thereto spaced to receive the inner ends of the arms 19 therebetween and the arms secured to the flanges by pins such as, 29 and 30.

To provide vertical support to the arms, angular truss braces 33 are attached at their lower ends to the sleeve and at the upper ends to the arms. At the lower ends, the sleeve has flanges 31 and 32 welded thereto to which braces 33 are pinned. The upper ends of the braces are pinned to plates 34 welded to the underside. of the arms 19. Three of the arms 20 connect at their outer ends to the peripheral masts 12, 13 and 14, and these arms have additional strengthening reinforcement as required. In the set-up shown in FIGS. 1 and 2, the arms have no additional reinforcement, but in the set-up shown in FIGS. 5, 6 and 8, additional reinforcement is provided. This reinforcement is required because the entire platform 10 is elevated ,to a new position by upward forces applied to the outer ends of the three arms which connect to the peripheral masts. The reinforcement for these three arms includes a horizontal radial brace 35 and a vertical brace 36 extending between the end of the brace 35 and the arm 19. 'At the,

upper end of the vertical brace 36, it is pinnedto the plate 34 as shown at 37, FIG. 6. Tension cables 38 are connected between the ends of the horizontal brace 35, and a lug 39 welded to the underside adjacent the end of the telescoping arm 20.

The inner ends of the horizontal braces 35 are connected to lugs 35a welded to the sleeve 26 and as will be observed from FIG. 6, when vertical lifting forces are applied to the three arms that extend to the masts, the arms are strengthened by the Cables 38 and braces 35 and 36, and the platform will be lifted asthe arms are moved upwardly.

Additional stabilizing support for the arms is provided by the beams 40, FIG. 3, which are pinned be tween the ends of adjacent arms 19, using the same pins 20a used forfixing the telescoping extension arms 20. At the center point of the tie beams 40 is a short sleeve to receive an additional plurality of telescoping extension arms 20 with pivotal latches 54, identical to those used in the basic scaffold angular truss braces 19,33, as shown in FIG. 3.

For supporting the platform in the incremental ele-, I vated positions, at the outer ends of the three arms which lead to the peripheral masts, are supporting collars 22. These are welded to the outer ends of the extendable arms 20 and are supported by locking pins 41 which pass through holes. 42 in the peripheral masts. The collars have short vertical slots 43 cut from their lower edges to help guide the insertion of the pins 41,:

and to permit lifting the collars.

For each elevated position of the platform, a height of circular silo is poured. The concrete wall 22a is supported by the outer forms 23 and inner forms 24, FIGS. 6 through 8.-The forms are curved, and rest on top of each other. When a sector of wall is poured and the concrete permitted to set, the lower forms are then removed andplaced on top of the upper forms, in the mannershown in FIG. 8, and when a new rise of forms is set up, the platform is again raised and fresh concrete is poured on top of the previously poured wall.

For elevating the platform'and all of the mechanism associated therewith, three hydraulic rams 44lare provided, each of which includes a hydraulic piston and cylinder. The cylinder has a collar 46 which is slidably journalled on the mast, FIG. 6, and pinned in place by a horizontal locking pin ,47 slid through one of the spaced holes 42 in the mast. The piston rod is connected at the upper end to a lug 45 welded on the outer end of the arm 20. The cylinder of the ram 44 is double ended with hydraulic fittings 48 and 49. There is a holding valve, not shown, at the lower fitting 48 of each cylinder to provide protection in the event a hydraulic line should fail in lifting. This will hold all cylinders from moving, preventing the one from falling or an unleveling of the platform. For raising the platform, oil under pressure is admitted through the lower fitting 48 to raise the platform and it is locked in the next position by reinserting the pin 41 in the next hole. The cylinder is then retracted to slide the collar 46 upwardly, and the pin 47 for the ram is inserted into the next hole so that the ram has a new elevated position. Each of the three rams 44 act in unison, and are supplied from a common source which has a flow divider, not shown, so an equal amount of oil flows to each of the rams so that the platform 10 is raised uniformly and stays horizontal.

For supplying hydraulic fluid to the elevating rams, and operating other hydraulic mechanism supported above the platform, a motor and pump 50 are supported below the platform, FIGS. 1, 2 and 3. An oil supply tank 51 is also carried beneath the platform with a valve bank and control panel 52, whereby the operator can operate the mechanism and its various additional functions which will be later herein described.

When the platform is raised by the hydraulic pistons and cylinders, it is elevated slightly past its new vertical position, and the pins 41 are then inserted, and the pistons and cylinders relax to permit the platform to settle into its locked position. The pins 41, of course, lock the arms extending to the peripheral masts in place. The intermediate arms are automatically locked by pivotal latches 54, FIGS. 6 and 9. The latches 54 are freely pivoted at the ends of the arms on a pivot pin 55. The latch is shown in its freely hanging position in FIG. 9 and has a weight 59 on its lower end. As the platform is raised upwardly, the locking end 56 of the latch will brush over the ring 57 on the concrete form 24 to slide past the ring. When the locking end 56 clears the ring, the latch will pivot to the position shown in FIG. 9, and when the platform is released by the hydraulic piston and cylinder, the locking end 56 will settle on top of the ring 57. The rings 57 are in the form of steel angles secured to lugs 58 on the inner surface of the forms. The latches 54 will stabilize the platform at the ends of the intermediate arms. Basically, because the platform is rigid with the mechanism employed, the platform is fully supported on the peripheral masts, but the additional stabilizing support offered by the rings on the concrete forms is helpful.

As the silo wall becomes higher, a workman stands in a stripping cage 60 below the platform 10 to remove the inner forms for raising to the platform for resetting. The stripping cage is supported on radial arms 61 and 64 connected at their inner ends to a rotary ring 62 which is mounted on a sleeve 63. Two sets of radial arms 61 and 64 are connected to the rotary ring 62 at 180 to each other. These arms support either two stripping cages at 180 to each other for two workmen for increased stripping production or one stripping cage with a counterweight opposite. The sleeve has upper and lower flanges, and the upper flange is connected by rods 65, FIGS. 6 and 8, to a lower flange on the platform sleeve 26 which is locked to the main mast by pins 66 and 67, FIGS. 6 and 8. These pins 66 and 67 are slid through slots in the sleeve 26 to pass through holes in the main mast when the platform is raised to each incremental horizontal position. The stripping cage, or cages 60 are at a position so that they can swing through 360 to carry the workman and/or men around to all positions, and permit the stripping of the inner forms for raising them on top of the uppermost forms to provide a new course of forms to pour another layer of concrete on top of the wall. For raising the lowermost forms and positioning them on top of the uppermost forms, a plurality of jib cranes are provided shown at 68, 69 and 70. The jib cranes are constructed similarly so that only one need be described in detail. As shown in FIG. 8, and as may be observed in the construction of thejib cranes in FIGS. 1, 2 and 6, each of the cranes has an inner boom 71 with an extension boom 80 locked in its telescoping extended position by pins 81. A plurality of holes, 80b are formed in the extension boom 80 for positioning the extension boom 80 for various diameters of building. An angular boom strut 72 provides vertical support for the arms 71 and a vertical strut 75 extends between 71 and 72. The inner ends of the boom 71 and the strut 72 are connected to rotary rings 73 and 74. These rings are stacked respectively on flanged sleeves 82 and 83. The sleeves are mounted on top of the platform Supporting sleeve 26 and have the main mast 11 passing therethrough. The sleeves are flanged at each end, and the flanges may be bolted to each other. In addition to the rings 73 and 74, additional rotary rings such as 84, 85, 86, 87, 90 and 111 are carried on the sleeves. Each of these rings have eyelets such as shown at 84a and a for the rings 84 and 85 for attaching other jib cranes.

The jib cranes have an inner winch 76 with a cable 77 wound thereon which passes over a sheave 78 on the outer end of the arm 80. The cable 77 passes downward and has a hook 79 on the lower end to hook onto a form to raise it such as shown at 23a in FIG. 8. The winch 76 is hydraulically driven and has an operating hydraulic motor, not shown, which is connected by hydraulic lines to the pump 50. Hydraulic fluid is controlled by the valve bank and control panel 52 to individually operate the winches for each of the jib cranes 68, 69 and 70, which are swung into position to lift the forms. The plurality of jib cranes are used to raise the lowermost outer forms either individually using individual jib cranes or in gang'us ing the plurality of jib cranes. Each individual jib crane 68, 69 and 70 have flow controls, not shown, on the corresponding valves such that flow can be adjusted to allow the jib cranes to be operated individually or in unison at identical vertical speeds with central control. As with the inner forms, the lowermost outer forms 23 are raised on top of the uppermost outer forms to provide a new course of forms to pour another layer of concrete on top of the wall.

The upper boom can be extended by sliding the arm 80 in or out to align the outer sheave with the load to be lifted and different extension settings can be used for different diameter silos or tanks.

For elevating the concrete from the ground to the distributing cart 41, a yoke supported crane boom 89 is provided attached at its inner end to a ring 90 pivotally carried on the upper sleeve 82, FIGS. 1 and 2. The boom 89 has an outer track end 94 which is angled downwardly. On the end is a small trolley 97 carrying a sheave 95. A cable 103 originates on a winch 104 at the inner end of the boom 89, passes over the sheave 95, downwardly over a sheave 98 having a hook 99 thereon, and up to be anchored at 101 on the trolley.

.The winch 104 is hydraulically driven, and the crane is used to lift concrete buckets. When the workman operates the winch to drop the pulley, it will be loaded at ground level, and then pulled upwardly. The bucket shown at 105 in FIG. 1 is provided with handles and is filled on the ground. When the bucket reaches the upper end of the travel so that the sheave 98 engages the sheave 95, the trolley 97 will begin to travel inwardly on the angled portion 94 until it hits an idler sheave 102 over which the cable is passed. At that point, the winch will be stopped and the head of the bucket will be positioned over the cart 41 where it will be emptied into the cart. With reversal of the winch, the bucket will again travel outwardly and then downwardly. With this arrangement, only a single winch is required to accommodate vertical movement of the bucket to the proper elevation and then horizontal movement.

For providing additional vertical support to the concrete boom, a yoke 91, FIGS. 1 and 2, is provided having wheels 92 and 93 at its lower end, which ride on the platform. The operator of the distributor cart stands on a platform 108 and operates controls 106 for driving the cart in rotation. When the cart is filled, the operator moves the concrete discharge spout 109 outwardly over into alignment with the top of the forms, and with the controls 106, drives the cart forwardly in a circular path around the platform to distribute concrete. The cart is supported on wheels 107 and is guided at the outer end of a radial cart arm 110 secured at its inner end to a ring 111 on the sleeve 83. Hydraulic supply cables are provided from the pump 50 so that the same pump and motor operate all of the hydraulic equipment.

When the building has been completed, the distributa ing cart 41 and yoke supported crane boom 89 or hoses 115 used when pumping, stripping cage or cages 60 and all inner and outer forms 24 and 23 are removed and lowered over the outside of the poured concrete wall to the ground using the plurality of jib cranes 68,69 and 70 operating outside the concrete wall. Thereupon, the jib crane extension booms 80 are drawn in and pinned to work on the inside of the concrete wall.

Thereupon, the platform and remaining elements of the mechanism are incrementally lowered using the hydraulic rams 44 in a similar but'opposite manner used in raising the platform and mechanism. As the platform and mechanism is lowered the brackets used to tie the peripheral masts to the concrete wall and theradial struts used to stabilize the center mast are removed and the individual lengths of the peripheral masts 12, 13 and 14 and the center mast 11 are removed as the mechanism moves below these individual lengths of mast. The radial struts and individual lengths of mast are then lowered to the bottom of the silo using the jib cranes 68, 69 and 70 operating within the building. When the platform and mechanism reaches the bottom of the building the unit is disassembled within the building into lengths and with the masts and radial struts are passed through an opening left in the wall. The plurality of telescoping extension arms of the platform are removed after all peripheral masts are removed allowing the platform to be rotated to allow the individual telescoping extension arms to align with the wall opening for removal.

As a brief summary of operation, for construction of a circular silo, the mechanism of FIGS. 1 and 2 is erected with the extensible outer portions 20 of the arms set to the diameter of the silo to be built and the peripheral masts set at a radius so thatthey will be just inside the silo wall. The first layer of forms 23 and 24, is set up, and concrete is placed into the traveling cart 41 by a crane 89, hoisting the concrete in a bucket 105. The crane travels peripherally around the forms. In lieu of elevating and placing concrete in the above mentioned manner, pumping of concrete from ground level through flexible hoses 115, FIG. 6, to the forms in their incrementally higher positions can be employed. Several vertical courses of forms are used and after the concrete is poured, it is permitted to set. Thereupon,

the lowermost inner and outer forms are stripped and set up on top of the top forms to prepare for pouring anotl'l'ef Eburse of concrete. The hoses 115 are supplied concrete by a pump shown schematically at 116.

Thereupon, the hydraulic cylinder and pistons 44 lift' the platform to the top of the course of forms just set. Before lifting, the pins 66 and 67 are removed to permit the platform to slide up on the center mast and to lift all of the associated equipmenuincluding the cranes above the platform and the stripping cages below the platform. When the platform has been lifted to where it is slightly above the next hole in the masts, the locking pins are slid into place, 41 for the peripheral masts, and 66 and 67 for the main mast. The pressure in the hydraulic rams 44 is then relaxed, and the platform and its associated mechanism are supported on the masts. Then the process is repeated each time a height of circular concrete has been poured. Elevation of the platform with each step and pouring is all hydraulically controlled by a workman. The mechanism is arranged so that a number of workmen can work rapidly, but since the operation is power operated, it can be used by a single workman should the occasion become necessary. The unit is completely stable being held against lateral movement within the concrete. The primary stresses which are vertical are supported on the masts and not on the concrete building or forms. The stability of the unit provides unusual safety to the workman and makes possible more rapid setting up and pouring than heretofore possible. Further, an important feature is the dexterity which permits using the. same unit to make silos of varying diameter. With increase in diameter, of course, additional platform pieces will be added so that the spaces between the arms will be closed. The platform and all of the associated operated mechanism is completely and firmly locked in its operating position by the pins which project through the holes in the. masts so that no accidental falling can occur. Further, the pins remain in place when the platform is raised soithat with any accidental failure of hydraulic pressure, the unit cannot fall. The entire system is unitary in the way it is supported so that all of the operating mechanism including the platform, the concrete dispersing equipment, and the cranes are carried by the same vertical masts. The parts are readily disassembled and reassembled, and being of straight construction, they can be easily carried in racks on a truck to readily be moved from one construction site to another. With hydraulic operation, the operating pump can be driven by a gasoline motor or it can be electrically operated where the buildings are to be constructed in an area where electri- Cal power is available.

We claim as our invention:

1. A scaffold mechanism for constructing a cylindrical building such as a concrete silo comprising in combination:

a horizontal generally circular platform means for .distributing construction ingredients to the circular wall of a silo being of a size with the edges extending close to the inner silo wall,

a plurality of peripherally located ground supported vertical mast means for positioning immediately adjacent the inside of the circular wall for supporting the weight of said platform means within said fluid pressure operated power elevation means for incrementally raising said platform means mounted on said mast means;

and locking means independent of said power means for supportingly locking said platform means to said mast means between operation of said power means.

2. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 1:

wherein said locking means includes cross pins extending through said mast means.

3. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 1:

wherein said platform means includes a plurality of radially extending platform arms with horizontal supporting surfaces therebetween.

4. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 1:

wherein said platform means is radially expandable for constructing buildings of selectable predetermined diameters.

5. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 1:

wherein said platform means includes a plurality of radially extending arms with telescopically extensible arms for the radial arms to accommodate the construction of cylindrical buildings of varying diameters.

6. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 1:

wherein said platform means includes a plurality of radially extending arms and circumferential reinforcing means extend between the arms.

7. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 1:

including a hydraulic pump carried on said platform means connected to said power elevation means.

8. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 1:

wherein said mast means includes a main center mast;

said platform means includes a plurality of radially extending arms with certain of said arms in alignment with said peripheral masts;

and locking means for supporting intermediate arms on forms on the cylindrical wall of the building.

9. A scaffold mechanism for constructing a cylindri cal building such as a concrete silo constructed in accordance with claim 8:

and including forms having horizontally extending Circumferential support rings thereon for lockingly engaging the distal ends of the arms of the platform means.

10. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 9:

wherein said second locking means includes pivotal links which pass over the rings as the platform means moves upwardly and lockingly engage the rings for vertically supporting the platform arms on the rings. 11. A scaffold mechanism for constructing a cylindrical building such as a concrete silo comprising in combination:

a material support means for supporting construction equipment for constructing a circular vertical wall;

circumferentially spaced vertical ground supported mast means radially within the wall for vertically supporting said support means independent of the wall;

horizontal support being afforded by radial engagement of said support means with the wall;

power means for elevating said support means relative to said mast means;

and locking means independent of said power means for locking said support means to said mast means intermittently of operation of said power means.

12. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 11:

wherein said mast means comprises at least three circumferentially spaced vertical masts.

13. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 11:

wherein said mast means includes a center mast.

14. A scaffold mechanism for constructing a cylindrical building such as a concrete silo comprising in combination:

a center ground supported mast extending vertically upwardly;

a crane means having a radially extending boom supported on said center mast;

a plurality of peripherally located ground supported vertical mast means for positioning immediately adjacent the inside of the circular wall of a concrete silo;

a horizontal generally circular platform means for distributing construction ingredients to the circular wall of a silo vertically slidable on said mast means and on said center mast;

power elevating means on said mast means engageable with the platform means for incrementally elevating the platform means;

and means for locking said platform means to said center mast and said mast means intermittent of the operation of said power elevating means.

15. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 14:

and including a sleeve on said center mast with a plurality of rings on said sleeve with at least one of said rings supporting a crane means for rotation about said center mast.

16. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 14:

including a plurality of sleeves on said center mast;

each of said sleeves having a plurality of rings rotatably mounted thereon;

means locking said sleeves in a predetermined vertical position on said center mast;

and means on said sleeves for supporting said crane means.

17. A scaffold mechanism for constructing a cylindricrane means includes a plurality of radially extendcal building such as a concrete silo constructed in acing eyelets on the rings for connection of the crane corclance with claim 16: means wherein said means on the sleeves for supporting the 

1. A scaffold mechanism for constructing a cylindrical building such as a concrete silo comprising in combination: a horizontal generally circular platform means for distributing construction ingredients to the circular wall of a silo being of a size with the edges extending close to the inner silo wall; a plurality of peripherally located ground supported vertical mast means for positioning immediately adjacent the inside of the circular wall for supporting the weight of said platform means within said wall; lateral stabilizing means at the edge of the platform for engagement with the silo wall; said mast means laterally supported with lateral support afforded by engagement of said lateral stabilizing means; fluid pressure operated power elevation means for incrementally raising said platform means mounted on said mast means; and locking means independent of said power means for supportingly locking said platform means to said mast means between operation of said power means.
 2. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 1: wherein said locking means includes cross pins extending through said mast means.
 3. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 1: wherein said platform means includes a plurality of radially extending platform arms with horizontal supporting surfaces therebetween.
 4. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 1: wherein said platform means is radially expandable for constructing buildings of selectable predetermined diameters.
 5. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 1: wherein said platform means includes a plurality of radially extending arms with telescopically extensible arms for the radial arms to accommodate the construction of cylindrical buildings of varying diameters.
 6. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 1: wherein said platform means includes a plurality of radially extending arms and circumferential reinforcing means extend between the arms.
 7. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 1: including a hydraulic pump carried on said platform means connected to said power elevation means.
 8. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 1: wherein said mast means includes a main center mast; said platform means includes a plurality of radially extending arms with certain of said arms in alignment with said peripheral masts; and locking means for supporting intermediate arms on forms on the cylindrical wall of the building.
 9. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 8: and including forms having horizontally extending circumferential support rings thereon for lockingly engaging the distal enDs of the arms of the platform means.
 10. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 9: wherein said second locking means includes pivotal links which pass over the rings as the platform means moves upwardly and lockingly engage the rings for vertically supporting the platform arms on the rings.
 11. A scaffold mechanism for constructing a cylindrical building such as a concrete silo comprising in combination: a material support means for supporting construction equipment for constructing a circular vertical wall; circumferentially spaced vertical ground supported mast means radially within the wall for vertically supporting said support means independent of the wall; horizontal support being afforded by radial engagement of said support means with the wall; power means for elevating said support means relative to said mast means; and locking means independent of said power means for locking said support means to said mast means intermittently of operation of said power means.
 12. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 11: wherein said mast means comprises at least three circumferentially spaced vertical masts.
 13. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 11: wherein said mast means includes a center mast.
 14. A scaffold mechanism for constructing a cylindrical building such as a concrete silo comprising in combination: a center ground supported mast extending vertically upwardly; a crane means having a radially extending boom supported on said center mast; a plurality of peripherally located ground supported vertical mast means for positioning immediately adjacent the inside of the circular wall of a concrete silo; a horizontal generally circular platform means for distributing construction ingredients to the circular wall of a silo vertically slidable on said mast means and on said center mast; power elevating means on said mast means engageable with the platform means for incrementally elevating the platform means; and means for locking said platform means to said center mast and said mast means intermittent of the operation of said power elevating means.
 15. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 14: and including a sleeve on said center mast with a plurality of rings on said sleeve with at least one of said rings supporting a crane means for rotation about said center mast.
 16. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 14: including a plurality of sleeves on said center mast; each of said sleeves having a plurality of rings rotatably mounted thereon; means locking said sleeves in a predetermined vertical position on said center mast; and means on said sleeves for supporting said crane means.
 17. A scaffold mechanism for constructing a cylindrical building such as a concrete silo constructed in accordance with claim 16: wherein said means on the sleeves for supporting the crane means includes a plurality of radially extending eyelets on the rings for connection of the crane means. 